Collision avoidance using dynamic target volume allocation

ABSTRACT

A collision is avoided between a new Flashcopy backup and an existing Flashcopy target volume containing an older Flashcopy backup being ingested during one of a mount operation, a restore operation, and a clone operation by dynamically allocating a new Flashcopy target volume for the new Flashcopy backup.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general computing systems, and moreparticularly to, systems and methods for collision avoidance usingdynamic target volume allocation.

2. Description of the Related Art

In today's society, computer systems are commonplace. Computer systemsmay be found in the workplace, at home, or at school. Computer systemsmay include data storage systems, or disk storage systems, to processand store data. Large amounts of data have to be processed daily and thecurrent trend suggests that these amounts will continue beingever-increasing in the foreseeable future. Moreover, data, data files,and/or data records are also required to be stored, retained, and/orsaved for various periods of time for subsequent retrieval and/or use.Efficiently storing and/or recycling the data, data files, and/or datarecords data is a key problem to solve, and therefore, a need exists toimprove the data storage utilization and recycling.

SUMMARY OF THE INVENTION

In one embodiment, a method is provided for a mount, clone, and/orrestore task and ingest into a secondary repository collision avoidanceusing dynamic target volume allocation using a processor device in acomputing environment. In one embodiment, by way of example only,avoiding a collision between a new Flashcopy backup and an existingFlashcopy target volume containing an older Flashcopy backup beingingested during one of a mount operation, a restore operation, and aclone operation by dynamically allocating a new Flashcopy target volumefor the new Flashcopy backup.

In another embodiment, a computer system is provided for a mount, clone,and/or restore task and ingest into a secondary repository collisionavoidance using dynamic target volume allocation using a processordevice, in a computing environment. The computer system includes acomputer-readable medium and a processor in operable communication withthe computer-readable medium. In one embodiment, by way of example only,the processor avoids a collision between a new Flashcopy backup and anexisting Flashcopy target volume containing an older Flashcopy backupbeing ingested during one of a mount operation, a restore operation, anda clone operation by dynamically allocating a new Flashcopy targetvolume for the new Flashcopy backup.

In a further embodiment, a computer program product is provided for amount, clone, and/or restore task and ingest into a secondary repositorycollision avoidance using dynamic target volume allocation using aprocessor device, in a computing environment. The computer-readablestorage medium has computer-readable program code portions storedthereon. The computer-readable program code portions include a firstexecutable portion that avoids a collision between a new Flashcopybackup and an existing Flashcopy target volume containing an olderFlashcopy backup being ingested during one of a mount operation, arestore operation, and a clone operation by dynamically allocating a newFlashcopy target volume for the new Flashcopy backup.

In addition to the foregoing exemplary method embodiment, otherexemplary system and computer product embodiments are provided andsupply related advantages. The foregoing summary has been provided tointroduce a selection of concepts in a simplified form that are furtherdescribed below in the Detailed Description. This Summary is notintended to identify key features or essential features of the claimedsubject matter, nor is it intended to be used as an aid in determiningthe scope of the claimed subject matter. The claimed subject matter isnot limited to implementations that solve any or all disadvantages notedin the background.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readilyunderstood, a more particular description of the invention brieflydescribed above will be rendered by reference to specific embodimentsthat are illustrated in the appended drawings. Understanding that thesedrawings depict only typical embodiments of the invention and are nottherefore to be considered to be limiting of its scope, the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating a computing system environmenthaving a pair of storage disks in which aspects of the present inventionmay be realized;

FIG. 2 is a block diagram showing an exemplary hardware structure of aFlashCopy cascade in a computer system according to the presentinvention in which aspects of the present invention may be realized;

FIG. 3 is a block diagram showing an exemplary hardware structure of adata storage system in a computer system according to the presentinvention in which aspects of the present invention may be realized;

FIG. 4 is a block diagram showing an exemplary hardware structure of aFlashCopy backup operation in a computer system according to the presentinvention in which aspects of the present invention may be realized;

FIG. 5 is a block diagram showing an exemplary hardware structure of aFlashCopy backup operation with target volumes and a repository in acomputer system in which aspects of the present invention may berealized;

FIG. 6 is a block diagram showing an exemplary hardware structure of aFlashCopy backup operation without dynamic volume allocation in acomputer system in which aspects of the present invention may berealized;

FIG. 7 is a block diagram showing an exemplary hardware structurereusing collision with a mount in a system with a first and secondrepository without dynamic volume allocation in a computer system inwhich aspects of the present invention may be realized;

FIG. 8 is a flowchart illustrating an exemplary method for efficientFlashCopy backup target volume allocation with reuse while ingestingFlashCopy backups into a repository in which aspects of the presentinvention may be realized;

FIG. 9 is a block diagram showing an exemplary hardware structure forreusing an existing space efficient flashcopy target volume beforeallocating a new space efficient flashcopy target volume for dynamicvolume allocation for in a computer system in which aspects of thepresent invention may be realized;

FIG. 10 is a block diagram showing an exemplary hardware structure fordynamically allocating a new space efficient flashcopy target volume ifan existing space efficient flashcopy target volume is being ingested ina repository for in a computer system in which aspects of the presentinvention may be realized;

FIG. 11 is a block diagram showing an exemplary hardware structure fordynamically allocating a new space efficient flashcopy target volume ifan existing space efficient flashcopy target volume is being mounted bya host in a computer system in which aspects of the present inventionmay be realized;

FIG. 12A-B is a flowchart illustrating an additional exemplary methodfor dynamically allocating a FlashCopy backup target volume allocationfor reuse while ingesting FlashCopy backups into a repository in whichaspects of the present invention may be realized;

FIG. 13 is a flowchart illustrating an exemplary method for efficientFlashCopy backup target volume allocation from a shared resource poolwhile ingesting a FlashCopy backup in a repository using a processordevice in a computing environment in which aspects of the presentinvention may be realized;

FIG. 14 is a block diagram showing an exemplary hardware structure forefficient FlashCopy backup target volume allocation from a sharedresource pool while ingesting a FlashCopy backup in a repository in acomputer system in which aspects of the present invention may berealized;

FIG. 15A-B is a flowchart illustrating an additional exemplary methodfor efficient FlashCopy backup target volume allocation from a sharedresource pool in which aspects of the present invention may be realized;

FIG. 16A-B is a flowchart illustrating an additional exemplary methodfor efficient FlashCopy backup target volume allocation in which aspectsof the present invention may be realized;

FIG. 17 is a flowchart illustrating an exemplary method for efficientFlashCopy backup target volume allocation while ingesting a FlashCopybackup using a processor device in a computing environment;

FIG. 18 is a flowchart illustrating an exemplary method for collisionavoidance using dynamic target volume allocation in which aspects of thepresent invention may be realized;

FIG. 19A-B is a block diagram showing an exemplary hardware structurefor a file level restore operation;

FIG. 20 is a block diagram showing an exemplary hardware structure for ahigh level flow of a file level restore operation; and

FIG. 21 is a flowchart illustrating an exemplary method for collisionavoidance by dynamically reusing a target volume in which aspects of thepresent invention may be realized;

FIG. 22 is a flowchart illustrating an exemplary method collisionavoidance using dynamic target volume allocation from a shared resourcepool in which aspects of the present invention may be realized; and

FIG. 23 is a block diagram showing an exemplary hardware structure for ahigh level flow of a file level restore operation for collisionavoidance using dynamic target volume allocation from a shared resourcepool.

DETAILED DESCRIPTION OF THE DRAWINGS

Storage area network (SAN) is an architecture that is often used whenvery large amounts of data are to be stored in a reliable and securemanner. This technology allows networks to be created that support theattachment of remote computer storage devices such as disk arrays toservers in such a way that, to the operating system, the devices appearas locally attached. It is common in these networks to include a largeamount of redundancy, both in the data storage and in the hardwareconnections between the individual components.

A FlashCopy® function may be used for creating data redundancy. AFlashCopy® is a feature supported on various storage devices that allowsa user or an automated process to make nearly instantaneous copies ofentire logical volumes of data. A copy of a source disk is made on atarget disk. The copies are immediately available for both read andwrite access. A feature of FlashCopy® like implementations is theability to reverse the copy. That is, to populate the source disk of aFlashCopy® map with the contents of the target disk. With cascadedimplementations, in which a target disk later becomes the source diskfor a further FlashCopy®, this feature is complicated by the fact thatthe “grains” of data presented by a disk are located on a number oftarget/source disks “upstream” of the disk itself. This means that inorder for a disk to maintain the image it is presenting, it must haveaccess to all the disks containing these grains of data.

As mentioned, the FlashCopy® function may be used for creating dataredundancy. For example, the FlashCopy® function enables anadministrator to make point-in-time, full volume copies of data, withthe copies immediately available for read or write access. (FlashCopy isa registered trademark of International Business Machines Corporation inthe United States and other countries.) The FlashCopy® can be used withstandard backup tools that are available in the environment to createbackup copies on tape. A FlashCopy® function creates a copy of a sourcevolume on a target volume. This copy, as mentioned above, is called apoint-in-time (PIT) copy. When a FlashCopy® operation is initiated, arelationship is created between a source volume and target volume. Thisrelationship is a “mapping” of the source volume and the target volume.This mapping allows a point-in-time copy of that source volume to becopied to the associated target volume. The relationship exists betweenthis volume pair from the time that the FlashCopy® operation isinitiated until the storage unit copies all data from the source volumeto the target volume, or the relationship is deleted.

FlashCopy is often used for creating recovery points that areapplication consistent point in time copies of the production data.These recovery points can then be used in the event of production datacorruption. Because the production system is often of limited usefulnesswhen data corruption, occurs, the user frequently needs to be able torestore the production data immediately. Additionally users typically donot want to sacrifice any existing backups because restoring theproduction system may need to be re-triggered if mistakes are made whenrecovering the system. When the data is physically copied, a backgroundprocess copies tracks from the source volume to the target volume. Theamount of time that it takes to complete the background copy depends onvarious criteria, such as the amount of data being copied, the number ofbackground copy processes that are running and any other activities thatare presently occurring. The FlashCopy® function works in that the datawhich is being copied does not actually need to be copiedinstantaneously, it only needs to be copied just prior to an updatecausing on overwrite of any old data on the source volume. So, as datachanges on the source volume, the original data is copied to the targetvolume before being overwritten on the source volume. This copyingoperation is often referred to as a “copy on write” and is part of a“cleaning” in which dependency of the target volume on the source volumeis removed for the grain of data copied.

Therefore, a FlashCopy® is a feature supported on various storagedevices that allows a user or an automated process to make nearlyinstantaneous copies of entire logical volumes of data. A copy of asource disk is made on a target disk. The copies are immediatelyavailable for both read and write access. A common feature of FlashCopy®like implementations is the ability to reverse the copy. That is, topopulate the source disk of a FlashCopy® map with the contents of thetarget disk, typically in a restore operation.

There may be two types of point-in-time (PIT) backup processes used indata storage systems. One is called a clone and the other a snapshot. Aclone is a PIT copy where the target disk will hold a complete copy ofthe data that was on the source disk when the PIT copy was started. Whenthe copying of data from source to target completes, the target disk isindependent of the source.

Conversely, a snapshot is a PIT copy where the target only holds thechanged data necessary to present the PIT copy of the source. Data istypically only copied to the target disk if it is changed on the source.The target disk is generally dependent on some of the data on the sourcedisk in order to present the PIT copy.

It is also possible to use FlashCopy® in cascaded implementations, inwhich a target disk later becomes the source disk for a furtherFlashCopy® or vice versa. A cascade may be used to implement multiplePIT copies of a single data source. For example, with a data source Sand PIT copies of S taken at times t1, t2 and t3, then at time t1 thereis taken a PIT copy using data target T1 resulting in a cascade: S→T1.Then at time t2 there is taken a second PIT copy using data target T2and resulting in the cascade: S→T2→T1. This arrangement works because ifdata stored on T1 or S changes between times t1 and t2 the original datacan still be found on T1. Alternatively, if the data has not beenchanged between times t1 and t2, then both T1 and T2 will contain orpoint to the same data. Adding a third backup at t3 produces thecascade: S→T3→T2→T1.

As described herein, the present invention provides a solution fordynamic volume allocation, resource management, when the dynamic volumesare allocated and/or deleted using one of multiplicity of dynamic volumeallocation methods, such as using a high water and maximum (max)settings in IBM® Tivoli® FlashCopy Manager (FCM) device class and/or anallocation request explicitly approved by a computing system. It shouldbe noted that one embodiment of the computing system as used herein isthe IBM® Storwize® V7000 and IBM Storwize SVC and also a volume may alsobe the same thing as a vdisk as described herein. The Vdisk is the IBMSVC/V7000 term for a volume.

The dynamic volume allocation prevents collisions between PITs ingestinto a repository and subsequent backup tasks. The repository is alogical component in the SVC/V7000 system that contains deduplicated andcompressed PIT backups of production vdisks. A component called copydata services (CDS) ingests PIT backups of production vdisks into therepository as a background task. New vdisk(s), consistency group, andflashcopy mappings are allocated for subsequent backup task as opposedto reusing existing vdisk(s), consistency groups, and FlashCopy mappingsthat may be currently ingested into a repository.

As described herein, consistency groups address the issue whereapplication data resides across multiple volumes. By placing theFlashCopy relationships into a consistency group, commands can be issuedagainst all of the volumes residing in the group. This enables aconsistent point-in-time copy of all of the data even though it mayreside on physical separate volume. FlashCopy mappings may be members ofa consistency group, or they can be operated in a stand-alone manner,not as part of a consistency group. FlashCopy commands can be issued toa FlashCopy consistency group, which affects all FlashCopy mappings inthe consistency group, or to a single FlashCopy mapping if it is notpart of a defined FlashCopy consistency group.

It should be noted that there are at least 3 categories/types ofcollisions: 1) mount, instant restore, file level restore, and/or clonetasks collide with an ingest, 2) a flashcopy backup collides with aningest, and/or 3) a mount, restore, and/or clone task collides with aflashcopy backup.

Category 1 collisions are collisions resulting from mounting, instantlyrestoring, file level restoring and/or cloning operations colliding withan ingestion operation. As such the present invention provides thefollowing solutions to category 1 collisions.

First, in one embodiment, the present invention 1) avoids collisionbetween a mount, clone, file level restore, and/or an instant restore ofa backup residing on Space Efficient FlashCopy target volumes and aningest. The embodiment attempts to reuse existing resources (e.g.,volumes, fcmaps, consistency groups) after they have been ingested intothe repository first and allocate new resources if needed.

Second, in a further embodiment, the present invention avoids collisiona mount, clone, file level restore, and/or an instant restore of abackup residing on space efficient flashcopy target volumes and aningest. The present invention keeps a global pool of allocated resources(e.g., vdisks and consistency groups) available to reuse.

Third, in a further embodiment, the present invention avoids collision amount, clone, file level restore, and/or an instant restore of a backupresiding on space efficient flashcopy target volumes and an ingest. Thepresent invention attempts to reuse old vdisks in an SVC chain afterthey have been ingested into the repository. If none are available, thepresent invention uses vdisks from a global pool.

Category 2 collisions are collisions where the flashcopy backup in atarget volume collides with an ingest. As such the present inventionprovides the following solutions to category 2 collisions. First, in oneembodiment, the present invention avoids collision where the flashcopybackup in a target volume collides with an ingest by 1) always allocatesnew vdisks and delete old vdisks after they have been ingested into therepository.

Second, in a further embodiment, the present invention avoids collisionwhere the flashcopy backup in a target volume collides with an ingest by2) attempting first to reuse old vdisks in a SVC chain after the oldvdisks have been ingested into the repository. If none are available,the present invention allocates new vdisks.

Third, in a further embodiment, the present invention avoids collisionwhere the flashcopy backup in a target volume collides with an ingest by3) using vdisks from global pool that can be shared by multiple IBMTivoli FlashCopy Manager initiators (device classes).

Fourth, in a further embodiment, the present invention avoids collisionwhere the flashcopy backup in a target volume collides with an ingest by3) attempting first to reuse old vdisks in the SVC chain after they havebeen ingested into the repository. If none are available, the presentinvention uses vdisks from global pool.

Category 3 collisions are collisions resulting from mounting, restoring,and/or cloning operation colliding with a flashcopy backup. First, inone embodiment, the present invention avoids collisions betweenmounting, restoring, and/or cloning operation colliding with a flashcopybackup by 1) avoiding collision between reusing for backup and beingmounted at the same time. New volumes are always allocated for thebackup and old volumes are deleted. It is applicable to environmentswith and without a repository. New vdisks are always allocated and oldvdisks are deleted. If there is a repository, the present inventionwaits until after they have been ingested into the repository beforedeleting.

Second, in a further embodiment, the present invention avoids collisionsbetween mounting, restoring, and/or cloning operation colliding with aflashcopy backup by 2) avoiding collision between reusing for backup andbeing mounted at the same time. It is applicable to environments withand without a repository. The present invention first attempts to reuseold vdisks in a SVC chain after they have been ingested into therepository. If none of the old vdisks available, new vdisks areallocated.

Third, in a further embodiment, the present invention avoids collisionsbetween mounting, restoring, and/or cloning operation colliding with aflashcopy backup by 2) avoiding collision between reusing for backup andbeing mounted at the same time. It is applicable to environments withand without a repository. The present invention uses vdisks from aglobal pool that can be shared by multiple IBM Tivoli FlashCopy Managerinitiators (device classes).

Fourth, in a further embodiment, the present invention avoids collisionsbetween mounting, restoring, and/or cloning operation colliding with aflashcopy backup by 2) avoiding collision between reusing for backup andbeing mounted at the same time. It is applicable to environments withand without a repository. The present invention first attempts to reuseold vdisks in an SVC chain after the old vdisks have been ingested intothe repository if none of the old vdisks available, vdisks from theglobal pool are used.

The dynamic volume allocation prevents collisions between PIT ingestsinto the repository and mount, clone, instant restore, and/or file levelrestore operations. A mount task mounts a copy of a backup as opposed tothe original backup. Mounting a volume causes write modifications to it,which can impact the FlashCopy chain, the repository content, andingests into the repository.

The dynamic volume allocation prevents collisions between a mountoperation, a clone operation, file level restore and/or a instantrestore operation and subsequent FlashCopy backup tasks. The dynamicvolume allocation avoids the scenario where a FlashCopy backup on aspecific set of target vdisks is mounted but the target vdisks need tobe reused for a subsequent FlashCopy backup task. The dynamic volumeallocation allows multiple read/write independent mounts of the sameFlashCopy backup. By spawning independent copies of the originalFlashCopy backup PIT during mount processing, each mount operation isread/write accessible independent of one another. The dynamic volumeallocation removes the need for the user to manage pre-defined spaceefficient FlashCopy target volume sets when leveraging the capabilitiesof IBM Tivoli FlashCopy Manager. The dynamic volume allocation allows astable map of the latest FlashCopy to be obtained before clone ofproduction volume. The dynamic volume allocation avoids the scenariowhere a clone of a production can mean not being able to ingest thelatest FC backup PIT into the repository prior to initiating the cloneoperation.

For the dynamic volume allocation, the computing systems resources aremanaged. In one embodiment, the resources are limited in the SVC (e.g.,the SVC/V7000), and the maximum number of FlashCopy mappings per systemis 4096, but may be less in some edge cases due to memory consumption.The resources must be shared by multiple types of activities in the sameSVC. For the production activities by the customer there is no method tocontrol/limit resource consumption for this type of activity.

The computing system ingests the FlashCopy backups into the repository.The computing system mounts, clones, and/or restores the FlashCopybackups from repository and allocates implicit/explicit vdisks andFcmaps. For the Backup processing, the computing system allocates vdisksand Fcmaps as backup targets. The computing system also mounts, clones,and/or performs instant restore and file level restore from the SVCmanaged target volumes and allocates vdisks and Fcmaps. The resourcesnecessary to provide these capabilities may be controlled/limited by theTivoli FCM instance initiating the tasks or they may be managed nativelyby the computing system.

The computing system replicates production volumes and FlashCopy Backuprelated volumes using metro mirrors, global mirrors, and/or lowbandwidth global mirror capabilities. These tasks may be initiated froma Tivoli FCM Manager, which integrates with the target system or theymay be initiated and managed natively by the computer system.Additionally, the computing system may replicate repository content in amanner that only transfers unique blocks of data to the target system.

In one embodiment, there may be multiple IBM Tivoli FCM instances andthe multiple IBM Tivoli FCM instances can share the same SVC system, butdo not have visibility of one another.

As mentioned above, the present invention provides for when the dynamicvolumes are allocated and/or deleted. For the dynamic allocationscenario, new target volumes for FlashCopy backup tasks are allocatedeither by the IBM Tivoli FCM instance initiating the backup task or bythe native crash consistent SVC function that initiated the backup task.The IBM Tivoli FCM instance or the native crash consistent SVC functionneeds to allocate volumes for mount, clone, instant restore and/or filelevel restore of backup PITs on SVC/V7000 managed target volumes. TheIBM Tivoli FCM instance or the native crash consistent SVC functionallocates dummy volumes during clone of the production volumeprocessing. The IBM Tivoli FCM instance or native crash consistent SVCfunction makes a call to CDS to create implicit/explicit volumes whenusing a backup PIT in the repository for one of the followingoperations: a mount operation, an instant restore operation, a cloneoperation and/or a file level restore operation. In one embodiment, FCMinstance or the native crash consistent SVC function requests a CDS toallocate the volumes.

For the dynamic deletion scenario, the operations need to besynchronized with IBM Tivoli FCM. The FCM core asynchronously invokes aprocess to delete vdisks and Fcmaps that have the usability state set to“LOCALLY DELETED” (FCM core sets LOCALLY DELETED state when ingestmonitoring ends). The FCM device agent makes calls to the SVC/V7000 orto the CDS component residing in the SVC/V7000 to remove temporaryvdisks and Fcmaps. Dummy volumes are inserted into the chain and deletedby the LOCALLY DELTED usability state infrastructure of FCM core.

For managing the dynamic volume allocation using the high water and themaximum (max) settings in the IBM Tivoli FlashCopy Manager (FCM) deviceclass and/or an allocation request explicitly approved by a computingsystem, high-water and max configuration parameters are used and can beset at the FCM device class granularity. The device agent candynamically allocate up to a high-water during normal operations. Oncethe high water mark is passed, a warning message is raised (a signal isissued) indicating that the high water has been passed. The dynamicvolume allocation computing system enables rolling FlashCopy backups upto high-water during normal operating conditions and allows theFlashCopy backups to go up to the max setting in the case of collisionfrom mount, ingest, clone, restore, operations. For example, consider ahigh-water that is set equal to 3 with max equal to 5. The dynamicvolume allocation computing system allocates resources for up to 3FlashCopy backups during normal processing. If the high-water mark of 3is exceeded, a soft warning is issued when 3 is exceeded. In otherwords, dynamic volume allocation computing system allocates theFlashCopy backups with an “allocate with warning.” If resources for the4^(th) and 5^(th) FlashCopy backup instances are created, the dynamicvolume allocation computing system continues to allocate on a GUI butraises a message and/or generates log entry.

In one embodiment, the CDS code is the only entity that has whole viewof IBM Storwize SVC/V7000 system resource utilization. The CDS deviceagent in IBM Tivoli FCM asks the CDS function in the Storwize SVC/V7000for permission to allocate volumes. In the case of native SVC/V7000crash consistent data protection, the crash consistent managementfunction residing in the SVC/V7000 asks the CDS function in theSVC/V7000 for permission to allocate volumes. The CDS core code resolvesrequest into the number of vdisks and FlashCopy mappings that must becreated. For example, the FlashCopy backup of production applicationthat uses two data stores (vdisks on the SVC) resolves that two vdisks,two Fcmaps, and one consistency group would need to be created. Thedynamic volume allocation computing system checks the current resourceutilization (e.g., free memory, number of vdisks, Fcmaps, etc.) on theSVC for all crash consistent, application consistent, and productiontype activities. The dynamic volume allocation computing system approvesand/or disapproves the allocation request based on this data. Internallythe dynamic volume allocation computing system core code can deployvarious mechanisms to determine allocation outcome. The dynamic volumeallocation computing system deploys the internal high-water and maxsettings for each device class and dynamically adjusts the settingsbased on system load.

FIG. 1 illustrates the concept of a backup process using a storagecontroller 8 and two storage disks 10 and 12. The disks 10 and 12 couldform part of a larger array of disks, and may form part of an enterprisestorage solution. The disks 10 and 12 could be part of a storagesolution relating to a commercial website, for example. If at any time abackup needs to be made of the content of vdisk1, then a FlashCopyinstruction can be sent from the storage volume controller 8 to thatdisk 10, which defines a source disk 10 (vdisk1) and also a target disk12 (vdisk2), which is the target of the FlashCopy. The FlashCopyinstruction creates a point-in-time copy of the image of the specificvdisk, which is the source disk 10.

In the embodiment of FIG. 1, the source disk 10 of a first FlashCopyinstruction is vdisk1, and the target disk 12 is vdisk2. The FlashCopyinstruction starts the FlashCopy process, which creates a map 14 fromthe source disk 10 to the target disk 12. This map is labeled MAP 1 inthe Figure. The image of vdisk1 at this specific point in time is nowavailable on vdisk2. This creates a backup of the data on vdisk1, andalso allows tests and other administration tasks to be run on the dataof vdisk1, without the danger of losing any of the original data, as itis preserved on the original source disk.

When a FlashCopy is made, it creates a link between the two disks 10 and12, as defined by the map 14. Data may now be copied across in thebackground, with the additional requirement that any access to vdisk2(as the target disk 12) may immediately cause the relevant parts of theimage of vdisk1 to be copied across, and also any access to vdisk1 whichwould result in a change to the image stored by that disk 10 will alsocause the unaltered data to be immediately copied across to the targetdisk 12, prior to the change being made. In this way, the vdisk2, to anoutside user, stores the point in time copy of vdisk1, although data mayonly be physically copied across under the circumstances describedabove.

A storage volume that is the target volume of a backup process such as aFlashCopy function can also be the source volume of a further backupprocess, thus creating a cascade of storage volumes. In FIG. 2 there isshown an example of a FlashCopy cascade of three storage volumes 10, 12and 16, which are linked by FlashCopy maps 14. Each map 14 defines abackup process from a source volume to a target volume. Disk B isproviding a backup of disk A, and disk C is also providing a backup ofdisk A, through disk B. The FlashCopy functions 14 linking the differentstorage volumes may have been started at different times, which createdifferent point-in-time copies of the images stored by the respectivestorage volumes, or could have been started simultaneously.

In the FlashCopy cascade of A→B→C, where A, B and C are the disks in thecascade, as shown in FIG. 2, and the arrows (→) are the FlashCopy maps(the arrows may also represent the FlashCopy backup or FlashCopy maps inother Fig.'s described herein), then denoting (A, B) to be a FlashCopymapping from disk A to disk B, the cascade has maps (A, B) and (B, C).In this implementation of the cascade, any new data write to disk A willcause a write, that is a “copy write”, to disk B, as per the respectiveFlashCopy function, which is required to maintain the image on disk B.This writing to disk B will cause a further read, often referred to as a“clean read”, of disk B followed by another copy write to disk C. Inthis way a single write to the first storage volume 10 in the cascadecan result in a number of IO cleaning operations throughout the cascade.

When a cascade is created, the new maps and new storage volumes areinserted into the cascade, not added to the end of the cascade. In thecascade shown in FIG. 2, the first backup process started would be A→C.When the backup process A→B is then started, the new target storagevolume B is effectively “inserted” between the existing source storagevolume A and the existing target storage volume C. This “insertion” ispurely a logical construction illustrating the fact that target disk Cwill receive data writes from disk B, rather than disk A. This is how acascaded implementation differs from a conventional arrangement, whichwould have two independent maps from disk A. The storage volumecontroller may be operated so that the disks and maps are arranged sothat clones and snapshots are separated into different dependency chainsor cascades.

FIG. 3 is an exemplary block diagram 300 showing a hardware structure ofa data storage system in a computer system according to the presentinvention. Host computers 310, 320, 325, are shown, each acting as acentral processing unit for performing data processing as part of a datastorage system 300. The hosts (physical or virtual devices), 310, 320,and 325 may be one or more new physical devices or logical devices toaccomplish the purposes of the present invention in the data storagesystem 300. A Network connection 360 may be a fibre channel fabric, afibre channel point to point link, a fibre channel over ethernet fabricor point to point link, a FICON or ESCON I/O interface, any other I/Ointerface type, infiniband, SAS, a wireless network, a wired network, aLAN, a WAN, heterogeneous, homogeneous, public (i.e. the Internet),private, or any combination thereof. The hosts, 310, 320, and 325 may belocal or distributed among one or more locations and may be equippedwith any type of fabric (or fabric channel) (not shown in FIG. 3) ornetwork adapter 360 to the storage controller 340, such as Fibrechannel, FICON, ESCON, Ethernet, fiber optic, infiniband, SAS, wireless,coaxial adapters, and/or any other type network adapter. Data storagesystem 300 is accordingly equipped with a suitable fabric (not shown inFIG. 3) or network adapter 360 to communicate. Data storage system 300is depicted in FIG. 3 comprising storage controller 340 and storage 330.In one embodiment, the embodiments described herein may be applicable toa variety of types of computing architectures, such as in a virtualcluster management environment using the various embodiments asdescribed herein.

To facilitate a clearer understanding of the methods described herein,storage controller 340 is shown in FIG. 3 as a single processing unit,including a microprocessor 342, system memory 343 and nonvolatilestorage (“NVS”) 316, which will be described in more detail below. It isnoted that in some embodiments, storage controller 340 is comprised ofmultiple processing units, each with their own processor complex andsystem memory, and interconnected by a dedicated network within datastorage system 300. Storage 330 may be comprised of one or more storagedevices, such as storage arrays, which are connected to storagecontroller 340 by a storage network.

In some embodiments, the devices included in storage 330 may beconnected in a loop architecture. Storage controller 340 manages storage330 and facilitates the processing of write and read requests intendedfor storage 330. The system memory 343 of storage controller 340 storesthe operation software 350, program instructions and data, which theprocessor 342 may access for executing functions and method stepsassociated with managing storage 330, and executing the steps andmethods of the present invention. As shown in FIG. 3, system memory 343may also include or be in communication with a cache 345 for storage330, also referred to herein as a “cache memory”, for buffering “writedata” and “read data”, which respectively refer to write/read requestsand their associated data. In one embodiment, cache 345 is allocated ina device external to system memory 343, yet remains accessible bymicroprocessor 342 and may serve to provide additional security againstdata loss, in addition to carrying out the operations as describedherein.

In some embodiments, cache 345 is implemented with a volatile memory andnon-volatile memory and coupled to microprocessor 342 via a local bus(not shown in FIG. 3) for enhanced performance of data storage system300. The NVS 316 included in data storage controller is accessible bymicroprocessor 342 and serves to provide additional support foroperations and execution of the present invention as described in otherfigures. The NVS 316, may also be referred to as a “persistent” cache,or “cache memory” and is implemented with nonvolatile memory that may ormay not utilize external power to retain data stored therein. The NVSmay be stored in and with the cache 345 for any purposes suited toaccomplish the objectives of the present invention. In some embodiments,a backup power source (not shown in FIG. 3), such as a battery, suppliesNVS 316 with sufficient power to retain the data stored therein in caseof power loss to data storage system 300. In certain embodiments, thecapacity of NVS 316 is less than or equal to the total capacity of cache345.

Storage 330 may be physically comprised of one or more storage devices,such as storage arrays. A storage array is a logical grouping ofindividual storage devices, such as a hard disk. In certain embodiments,storage 330 is comprised of a JBOD (Just a Bunch of Disks) array or aRAID (Redundant Array of Independent Disks) array. A collection ofphysical storage arrays may be further combined to form a rank, whichdissociates the physical storage from the logical configuration. Thestorage space in a rank may be allocated into logical volumes, whichdefine the storage location specified in a write/read request.

In one embodiment, the storage system as shown in FIG. 3 may include alogical volume, or simply “volume,” may have different kinds ofallocations. Storage 330 a, 330 b and 330 n are shown as ranks in datastorage system 300, and are referred to herein as rank 330 a, 330 b and330 n. Ranks may be local to data storage system 300, or may be locatedat a physically remote location. In other words, a local storagecontroller may connect with a remote storage controller and managestorage at the remote location. Rank 330 a is shown configured with twoentire volumes, 334 and 336, as well as one partial volume 332 a. Rank330 b is shown with another partial volume 332 b. Thus volume 332 isallocated across ranks 330 a and 330 b. Rank 320 n is shown as beingfully allocated to volume 338—that is, rank 330 n refers to the entirephysical storage for volume 338. From the above examples, it will beappreciated that a rank may be configured to include one or more partialand/or entire volumes. Volumes and ranks may further be divided intoso-called “tracks,” which represent a fixed block of storage. A track istherefore associated with a given volume and may be given a given rank.

The storage controller 340 may include a FlashCopy backup module 355, aningestion module 357, a collision avoidance module 359, a target volumeallocation module 361, and a mapping module 363. The FlashCopy backupmodule 355, the ingestion module 357, the collision avoidance module359, the target volume allocation module 361, and the mapping module 363may be one complete module functioning simultaneously or separatemodules. The FlashCopy backup module 355, the ingestion module 357, thecollision avoidance module 359, the target volume allocation module 361,and the mapping module 363 may have some internal memory (not shown) andmay store unprocessed, processed, or “semi-processed” data. TheFlashCopy backup module 355, the ingestion module 357, the collisionavoidance module 359, the target volume allocation module 361, and themapping module 363 may work in conjunction with each and every componentof the storage controller 340, the hosts 310, 320, 325, and otherstorage controllers 340 and hosts 310, 320, and 325 that may be remotelyconnected via the storage fabric 360. Both the FlashCopy backup module355, the ingestion module 357, the collision avoidance module 359, thetarget volume allocation module 361, and the mapping module 363 may bestructurally one complete module or may be associated and/or includedwith other individual modules. The FlashCopy backup module 355, theingestion module 357, the collision avoidance module 359, the targetvolume allocation module 361, and the mapping module 363 may also belocated in the cache 345 or other components of the storage controller340.

The storage controller 340 includes a control switch 341 for controllingthe fiber channel protocol to the host computers 310, 320, 325, amicroprocessor 342 for controlling all the storage controller 340, anonvolatile control memory 343 for storing a microprogram (operationsoftware) 350 for controlling the operation of storage controller 340,cache 345 for temporarily storing (buffering) data, and buffers 344 forassisting the cache 345 to read and write data, a control switch 341 forcontrolling a protocol to control data transfer to or from the FlashCopybackup module 355, the ingestion module 357, the collision avoidancemodule 359, the target volume allocation module 361, and the mappingmodule 363 in which information may be set. Multiple buffers 344 may beimplemented to assist with the methods and steps as described herein.

In one embodiment, the host computers or one or more physical or virtualdevices, 310, 320, 325 and the storage controller 340 are connectedthrough a network adaptor (this could be a fibre channel) 360 as aninterface i.e., via a switch called “fabric.” The microprocessor 342 maycontrol the memory 343 to store command information from the clusterhost/node device (physical or virtual) 310 and information foridentifying the cluster host/node device (physical or virtual) 310. Thecontrol switch 341, the buffers 344, the cache 345, the operatingsoftware 350, the microprocessor 342, memory 343, NVS 316, the FlashCopybackup module 355, the ingestion module 357, the collision avoidancemodule 359, the target volume allocation module 361, and the mappingmodule 363 are in communication with each other and may be separate orone individual component(s). Also, several, if not all of thecomponents, such as the operation software 350 may be included with thememory 343. Each of the components within the devices shown may belinked together and may be in communication with each other for purposessuited to the present invention.

In one embodiment, the FlashCopying provides for completion of copyingthe first primary volume to the second primary volume to be signaledprior to data on the first primary volume being physically copied to thesecond primary volume. The system may include a first secondary volumeto asynchronously mirror the first primary volume, and a secondsecondary volume to asynchronously mirror the second primary volume. Thesystem includes a secondary storage controller device for the firstsecondary volume and the second secondary volume, and a secondary hostsystem to communicate directly with the secondary storage controllerdevice. The system includes a primary storage controller device for thefirst primary volume and the second primary volume and to communicatedirectly with the secondary host system. The primary storage controllerdevice is unaware of and is unable to directly communicate with thesecondary storage controller device.

Responsive to receiving a first command from a primary host systemspecifying that the first primary volume is to be flash-copied to thesecond primary volume, the primary storage controller device is toverify at least a first state of the first primary volume and the secondprimary volume to determine whether at least the first state permitssuch flash-copying. Responsive to successfully verifying at least thefirst state, the primary storage controller device is to send a firstquery to the secondary host system requesting whether the firstsecondary volume can be flash-copied to the second secondary volume.Responsive to unsuccessfully verifying at least the first state, theprimary storage controller device is to send a first response to theprimary host system indicating that the first command cannot befulfilled.

Yet, in an additional embodiment, there is a production volume P in astorage area network (SAN) volume controller (SVC), such as IBM®Storwize® SVC/V7000. FIG. 4 is a block diagram 400 showing an exemplaryhardware structure of a FlashCopy backup operation in a computer systemaccording to the present invention in which aspects of the presentinvention may be realized. Flashcopy backups of the production volume P(e.g., a source 402) are scheduled periodically. When a Flashcopy backupof P (e.g., the source 402) is initiated at time T0 within the SVC, aspace efficient FlashCopy target volume T0 is created. This may besignified by the following notation P→T0. The arrows (→), as usedherein, indicates the actual flashcopy map. The Flashcopyspace-efficient (SE) feature allocates storage space on an “as-needed”basis by using space on a target volume only when it actually copiestracks (or grains) from the source volume to the target volume. Withoutspace-efficient volumes, the Flashcopy function requires that all thespace on a target volume be allocated and available even if no data iscopied there. However, with space-efficient volumes, Flashcopy uses onlythe number of tracks (or grains) that are required to write the datathat is changed during the lifetime of the Flashcopy relationship, sothe allocation of space is on an “as-needed” basis. Becausespace-efficient Flashcopy volumes do not require a target volume that isthe exact size of the source volume, the Flashcopy SE feature increasesthe potential for a more effective use of system storage. Thespace-efficiency attribute may be defined for the target volumes duringthe volume creation process. A space-efficient volume can be createdfrom any extent pool that has already-created space-efficient storage.As long as the space-efficient source and target volumes have beencreated and are available, they can be selected when the Flashcopyrelationship is created.)

The flashcopy map is a bitmap 406 of changed grains between theproduction volume P and the space efficient target T0. There aredifferent Flashcopy options in the SVC. For example, as used in FIG. 4,a “no copy option” is used, which means that no background copy of allgrains takes place between P (e.g., the source 406) and T0. Only grainsthat are changed after the snapshot bitmap is created are copied to T0.A flashcopy start command is issued. When a Flashcopy backup of thesource 402 is initiated at time T0, a space efficient FlashCopy targetvolume 404 is created. The copy is immediately available after thebitmaps (metadata) 406 are built. The read/write to a copy is nowpossible. As depicted in FIG. 4, another backup T0+t is scheduled.Blocks that are not yet written to the target 404 are read from thesource 402. Before a write 408 to the source is performed, the data iscopied to the target 404.

Now, building off a FIG. 4, as illustrated in FIG. 5, T1 and T0 are notmounted by the host and are not changing. Therefore the flashcopy mapbetween T1 and T0 is frozen in time. The flashcopy map between P and T1is not frozen in time because the production volume P can be changingdue to writes from the host, which will follow the behavior FIG. 4. FIG.5 is a block diagram 500 showing an exemplary hardware structure of aFlashCopy backup operation with target volumes and a repository in acomputer system. Either the Tivoli Flashcopy manager or a native svccrash consistent data protection function schedules the backup schedulesFlashcopy backups of the production volume P 502. When a Flashcopybackup of P is initiated at time T0 within the SVC, a space efficientFlashCopy target volume T0 (the target volumes are illustrated as T0,depicted as 504D, T1, depicted as 504C, T2, depicted as 504B, and T3,depicted as 504A) is created. This is signified, for example, by thefollowing notation P→T0. The repository 506 is a logical entity withinthe SVC that ingests the content residing on the flashcopy targetvolumes 504. It does so by ingesting stable flashcopy maps and theassociated changed grains as a background task. The repository is alogical component in the SVC/V7000 system that contains deduplicated andcompressed PIT backups of production vdisks. A component called copydata services (CDS) ingests PIT backups of production vdisks into therepository as a background task. In FIG. 5, once T1 504C exists there isa stable map between T1 and T0; therefore T0 504D may be ingested intothe repository 506. The backups may continue. IBM Tivoli FlashCopymanager schedules application consistent snapshot backups. In oneembodiment, the present invention/computing system is built uponexisting copy services function available in storage controllers (e.g.,IBM storage controllers) to enable a revolutionary approach to addressthe expanding data protection and retention needs of customers asefficiently and economically as possible utilizing snapshot basedbackups while also enabling new customer use cases. The computing systemintegrates with a Flash Copy Manager (FCM) (e.g., Tivoli® FCM) in orderto provide application consistent snapshot support and also providescrash consistent snapshot support natively without the use of FCM.

The computing system architecture enables it to be integrated withdifferent storage controllers and host applications to provide anin-band solution which allows the computing system enabled storagecontroller to manage production data and have that same storagecontroller manage snapshot backups of the production data contained in arepository. The production data and repository are managed by thecomputing system enabled controller as internal and/or external storage.The computing system code running in the storage controller creates aninitial data reduced full copy of the production volumes in a repositoryusing data reduction techniques such as data deduplication and IBMStorwize Real Time Compression™ (RTC). The deltas between subsequentsnapshots are deduplicated and then compressed using RTC in therepository to further minimize capacity consumption and significantlyextend the amount of FlashCopy restore points that are retained in therepository. The repository and FCM metadata may be replicated to aremote location for disaster recovery. Existing SVC replicationtechniques may be leveraged to provide replication and disaster recoverycapabilities. Network bandwidth for this replication will bedramatically reduced because the repository only contains deduplicateddata. Also, the present invention computing system based replicationmethod that uses deduplication, RTC and other data reduction techniquesmay be used to further reduce the required network bandwidth. A copy ofthe production volume at any point in time can be recreated nearlyinstantly from the repository. Customers may mount a snapshot backup anduse a TSM client to offload the data to TSM server attached storage forlonger-term retention.

However, a current challenge of Flashcopy backups pertains to ingestingFlashcopy/snapshot backups in an SVC into a repository while alsogenerating new FlashCopy backups, as depicted in FIG. 6. Anotherchallenge arises when the existing space efficient flashcopy targetvolume that needs to be reused is mounted by the host. It is notpossible to reuse the existing space efficient flashcopy target volumefor a new FlashCopy (FC) backup since it would overwrite the contentthat is being presented to the host. Thus, if an existing spaceefficient flashcopy target volume (e.g., T0) is being mounted, new spaceefficient flashcopy target volumes need to be dynamically allocated asindicated in FIG. 11.

FIG. 6 is a block diagram 600 showing an exemplary hardware structure ofa FlashCopy backup operation without dynamic volume allocation in acomputer system. As illustrated, a precondition has 3 Flashcopy SEtarget vdisks predefined as a space efficient FlashCopy target volumesT0, T1, T2, and T3 (the target volumes are illustrated as T0, depictedas 604D, T1, depicted as 604C, T2, depicted as 604B, and a next FCbackup/T3, depicted as 604A). The challenge is the target vdisk T0 needsto be reused but T0 604D has not been fully ingested into the repository606. The repository 606 is a logical entity within the SVC that ingeststhe content residing on the flashcopy target volumes 604. IBM TivoliFCM, native crash consistent data protection function, or any othersuitable backup scheduler schedules Flashcopy backups of the productionvolume P. The following notation, by way of example only, P→T0 signifiesthis. Also, there are FlashCopy backups between next FC backup→T2,T2→T1, and T1→T0. It does so by ingesting stable flashcopy maps and theassociated changed grains as a background task. There is a resourceconflict between the next FlashCopy (FC) backup (e.g., T3 604A) and therepository 606 because T0 is needed to be reused for the for the nextFlashCopy (FC) backup but T0 604D is being ingested by the repository606.

Another challenge arises when the target vdisk that needs to be reusedis being used as the source of a mount, clone, instant restore, or filelevel restore operation. It is not possible to reuse the target vdiskfor a new backup since it would overwrite the content that is beingpresented to the host. FIG. 7 illustrates this use case. FIG. 7 is ablock diagram 700 showing an exemplary hardware structure reusingcollision with a mount in a system with a first and second repositorywithout dynamic volume allocation in a computer system. The FCM deviceagent asks for permission to reuse T0. As illustrated, a preconditionhas 3 Flashcopy SE target vdisks predefined as a space efficientFlashCopy target volumes T0, T1, T2, and T3 (the target volumes areillustrated as T0, depicted as 704D, T1, depicted as 704C, T2, depictedas 704B, and a next FC backup/T3, depicted as 704A). The challenge isthe target vdisk T0 needs to be reused but T0 704D is being mounted to ahost 708 (e.g., T0 needs to be reused for the next FC backup 704D but T0704A is being used for a mount task). The repository 706 is a logicalentity within the SVC that ingests the content residing on the flashcopytarget volumes 704. schedules Flashcopy backups of the production volumeP. The following notation, by way of example only, P→T0 signifies this.Also, there are FlashCopy backups between next FC IBM Tivoli FCM, nativecrash consistent data protection function, or any other suitable backupscheduler backup→T2, T2→T1, and T1→T0. There is a resource conflictbetween the next FlashCopy (FC) backup (e.g., T3 704A) because T0 isneeded to be reused for the next FlashCopy (FC) backup but T0 704D isbeing used for a mount task for the host 708. In short, as described inFIG. 7, FIG. 7 is addressing collision avoidance with a mount and aningest collision.

In one embodiment, the present invention provides a solution thatattempts to reuse existing FlashCopy target volumes that containprevious FlashCopy/snapshot backups that have already been ingested intothe repository and that are not being used as the source for a mount,clone, instant restore and/or file level restore task. By attempting toreuse existing resources (vdisks, FlashCopy maps, and consistencygroups) processing overhead may be minimized when compared to alwaysallocating new volumes for this use case. In addition there is no needto track resources in a global manner. Instead IBM Tivoli FCM canattempt to reuse resources that already exist in the dedicated deviceclass.

FIG. 8 is a flowchart illustrating an exemplary method 800 for efficientFlashCopy backup target volume allocation with reuse while ingestingFlashCopy backups into a repository in which aspects of the presentinvention may be realized. The method 800 begins (step 802) bydynamically allocating a target volume for a new FlashCopy backup byreusing an existing FlashCopy target volume containing older FlashCopybackups that have been previously ingested into a repository and are notcurrently being used as a source for at least one of a mount task, aclone task, and a restore task prior to issuing a new target volume(step 804). The method 800 ends (step 806).

As part of the Flashcopy backup processing, the FCM attempts to reuseexisting target vdisks before allocating new target vdisks, asillustrated in FIG. 9. On the other hand, if T0 is being ingested intothe repository, a new target vdisk T3 is allocated for the new backuptask as indicated in FIG. 10.

FIG. 9 is a block diagram showing an exemplary hardware structure 900for reusing an existing space efficient flashcopy target volume beforeallocating a new space efficient flashcopy target volume for dynamicvolume allocation for in a computer system. As illustrated, aprecondition has 3 Flashcopy SE target vdisks predefined as a spaceefficient FlashCopy target volumes T0, T1, and T2 (the target volumesare illustrated as T0, depicted as 904D, T1, depicted as 904C, T2,depicted as 904B, and T3/a next FC backup, depicted as 904A). Fordynamic volume allocation of the target volumes, target vdisk T0 904D isreused because T0 904D has previously been ingested into the repository906. The repository 906 is a logical entity within the SVC that ingeststhe content residing on the flashcopy target volumes 904. The productionvolume P 902 schedules Flashcopy backups of the production volume P. Thefollowing notation, for example, P→T0, signifies this. Also, there areFlashCopy backups between next FC backup→T2, T2→T1, and T1→T0.Simultaneously, while T0 is being reused for the for the next FlashCopy(FC) backup, the flashcopy target volume T1 904C is being ingested intothe repository. Collisions are avoided while T0 is being reused for thenext FlashCopy (FC) backup 904A and while the flashcopy target volume T1904C is being fully ingested into the repository.

If T0 is being ingested into the repository when a new FlashCopy backupis required, a new target vdisk T3 is allocated for the new backup taskas indicated in FIG. 10. This is because there is a resource conflictbetween the next FlashCopy (FC) backup and the existing FlashCopy backuptarget volume (e.g., T0) that is being ingested into the repository.FIG. 10 is a block diagram showing an exemplary hardware structure 1000for dynamically allocating a new space efficient flashcopy target volumeif an existing space efficient flashcopy target volume is being ingestedin a repository. As illustrated, a precondition, by way of example only,has 3 Flashcopy SE target vdisks predefined as a space efficientFlashCopy target volumes T0, T1, T2, and T3 (the target volumes areillustrated as T0, depicted as 1004D, T1, depicted as 1004C, T2,depicted as 1004B, and a next FC backup (T3), depicted as 1004A). InFIG. 10, the flashcopy target volume T0 is being ingested into therepository so a new target vdisk T3 1004A is allocated for the newflashcopy backup task. The new space efficient flashcopy target volumeT3 1004A is dynamically created in the same pool as the existing spaceefficient flashcopy target volumes 1004. The dynamic volume allocationcomputing system 1000 allows a customer to meet RPO. The dynamic volumeallocation computing system 1000 is allowed to continue to ingestexiting backup PIT residing on the Flashcopy SE target vdisks 1004.

Either the Tivoli Flashcopy manager or a native svc crash consistentdata protection function schedules the backup schedules Flashcopybackups of the production volume P 1002. For dynamic volume allocationof the target volumes, since target vdisk T0 100DA is being ingestedinto the repository 1006. This is signified by the following notationP→T0. Also, there are FlashCopy backups between next FC backup→T2,T2→T1, and T1→T0. Since T0 is being ingested into the repository, a newspace efficient flashcopy target volume T3 1004A is dynamically createdin the same pool as the existing space efficient flashcopy targetvolumes 1004 for the for the next FlashCopy (FC) backup. In short, a newspace efficient flashcopy target volume is allocated to avoid acollision with an existing space efficient flashcopy target volume thatis being ingested into the repository.

FIG. 11 is a block diagram showing an exemplary hardware structure 1100for dynamically allocating a new space efficient flashcopy target volumeif an existing space efficient flashcopy target volume is being mountedby a host in a computer system. The FCM device agent asks for permissionto reuse T0. As illustrated, by way of example only, a precondition has3 Flashcopy SE target vdisks predefined as a space efficient FlashCopytarget volumes T0, T1, T2, T3 (the target volumes are illustrated as T0,depicted as 1104D, T1, depicted as 1104C, T2, depicted as 1104B, andT3/a next FC backup, depicted as 1104A). The challenge is the targetvdisk T0 needs to be reused but T0 1104D is being mounted to a host 1108(e.g., T0 needs to be reused for the next FC backup 1104A but T0 1104Dis being used for a mount task). The repository 1106 is a logical entitywithin the SVC that ingests the content residing on the flashcopy targetvolumes 1104. IBM Tivoli FCM, native crash consistent data protectionfunction, or any other suitable backup scheduler schedules Flashcopybackups of the production volume P. The following notation, for example,P→T0 signifies this. Also, there are FlashCopy backups between nextT3→T2, T2→T1, and T1→T0. It does so by ingesting stable flashcopy mapsand the associated changed grains as a background task. There is aresource conflict between the next FlashCopy (FC) backup (e.g., T31104A) because T0 is needed to be reused for the next FlashCopy (FC)backup T3 1104A but T0 1104D is being mounted by the host 1108.

To avoid the next/new FlashCopy backup from being rejected until themounting of T0 is completed, and for avoiding a customer to miss arecovery point objective (RPO)/backup window, a new space efficientflashcopy target volume T3 1104A is dynamically created in the same poolas the existing space efficient flashcopy target volumes 1104 for thefor the next FlashCopy (FC) backup. In short, a new space efficientflashcopy target volume is allocated to avoid a collision with anexisting space efficient flashcopy target volume that is being mountedto a host 1108. It should be noted that T1 1104C is a also an existingspace efficient flashcopy target volume 1104 that is being ingested intoa repository, as depicted in FIG. 11 for illustration purposes only, andtherefore presents resource conflict between the next FlashCopy (FC)backup (e.g., T3 1104A) and the repository 1108 because T1 is beingingested by the repository 1106, which also requires a new spaceefficient flashcopy target volume T3 1104A to be dynamically created inthe same pool as the existing space efficient flashcopy target volumes1104, if it was desired to use T1 rather than T0.

FIG. 12A-B is a flowchart illustrating an additional exemplary method1200 for dynamically allocating a FlashCopy backup target volumeallocation for reuse while ingesting FlashCopy backups into a repositoryin which aspects of the present invention may be realized. The method1200 begins (start 1202) by verifying a state of production targetvolumes (in a partition phase) (step 1204). The method 1200 determinesif the verification process was a success (step 1206). If no, the method1200 raises an error condition (step 1250) and then the method 1200 ends(step 1252). If the state of production target volumes is verified, themethod 1200 determines if existing space efficient flashcopy targetvolumes are being ingested (step 1208). If yes, then in a prepare phase,the method 1200 dynamically allocates a new space efficient flashcopytarget volume(s) (step 1212). In the prepare phase following step 1212,the method 1200 determines if the new space efficient flashcopy targetvolume was successfully allocated (step 1214). If no, the method 1200dynamically cleans up any dynamically allocated resources (step 1240).If yes (from step 1214), the method 1200 creates a consistency group(step 1216). The method 1200 determines if the consistency group wassuccessfully created (step 1218). If no, the method 1200 dynamicallycleans up any dynamically allocated resources (step 1240). If yes (fromstep 1218), the method 1200 creates FlashCopy backup mappings (step1228).

Returning to step 1208, if existing space efficient flashcopy targetvolumes are not being ingested (step 1208), the method 1200 determinesif the existing space efficient flashcopy target volume(s) are beingused by a FlashCopy manager (FCM) (step 1210). The FCM may perform amount operation, a clone operation, an instant restore operation, and/ora file level restore operation on the existing space efficient flashcopytarget volume(s) that needs to be reused. If yes, the method 1200 goesto step 1212. If no, the method 1200 terminates/stops a consistencygroup (step 1220). The method 1200 determines if the consistency groupwas successfully terminated/stopped (step 1222). If no, the method 1200raises an error condition (step 1250) and ends (step 1252). If yes, themethod 1200 deletes FlashCopy backup mappings (step 1224). The method1200 determines if the FlashCopy backup mappings were deleted (step1226). If no, the method 1200 raises an error condition (step 1250) andends (step 1252). If yes, the method 1200 creates FlashCopy backupmappings (step 1228). The method 1200 determines if the FlashCopy backupmappings were successfully created (step 1230). If no, the method 1200dynamically cleans up any dynamically allocated resources (step 1240),raises an error condition (step 1250) and ends (step 1252). If yes (fromstep 1230), the method 1200 initializes a consistency group (e.g., apre-start) (step 1232). The method 1200 determines if the consistencygroup was successfully initialized (step 1234). If no, the method 1200dynamically cleans up any dynamically allocated resources (step 1240),raises an error condition (step 1250) and ends (step 1252). If yes (fromstep 1234), the method 1200 starts a FlashCopy backup (in a Flash phase)(step 1236). The method 1200 determines if the FlashCopy backup wassuccessfully started (step 1238). If no, the method 1200 dynamicallycleans up any dynamically allocated resources (step 1240), raises anerror (step 1250) and ends (step 1252).

If yes (from step 1238), the method 1200, in the flash phase, notifies acopy data services (CDS) of the new space efficient flashcopy backup(step 1242). The method 1200 determines if the CDS was successfullynotified of the new space efficient flashcopy backup (step 1244). If no,the method 1200 raises an error condition (step 1250) and then themethod 1200 ends (step 1252). If yes (from step 1244), the method 1200,in a verify/verification phase, updates the usability of states of thespace efficient flashcopy backups and/or enables monitoring of thestates and/or existing space efficient flashcopy backup target volumes(step 1246). The method 1200 determines if the usability of states ofthe existing space efficient flashcopy backups was successfully updatedand/or the monitoring of the states and/or existing space efficientflashcopy backup target volumes was successfully enabled (step 1248). Ifno, the method 1200 raises an error condition (step 1250). The method1200 ends (step 1252).

In one embodiment, the present invention keeps and/or maintains a globalpool of FlashCopy target volumes and consistency groups that are usedfor new FlashCopy backup tasks upon encountering a collision whileingesting an existing FlashCopy Backup into a repository. By attemptingto reuse existing resources (e.g., virtual disks “vdisks”, andconsistency groups) processing overhead may be minimized when comparedto always allocating new volumes for this use case or when compared toreusing existing target volumes that are only within the scope of thesame FlashCopy chain. In other words, the global pool may be used bymultiple IBM Tivoli FCM device classes using the same storagecontroller.

FIG. 13 is a flowchart illustrating an exemplary method 1300 forefficient FlashCopy backup target volume allocation from a sharedresource pool while ingesting a FlashCopy backup in a repository using aprocessor device in a computing environment. The method 1300 begins(step 1302) by maintaining and/or keeping a global pool of FlashCopybackup target volumes and/or a consistency group in the global pool ofFlashCopy backup target volumes for use by a new FlashCopy backup uponencountering a collision while an existing FlashCopy target volumecontaining older FlashCopy backups are being ingested into therepository for dynamically allocating a target volume for the newFlashCopy backup (step 1304). The method 1300 ends (step 1306).

FIG. 14 is a block diagram showing an exemplary hardware structure 1400for efficient FlashCopy backup target volume allocation from a sharedresource pool while ingesting a FlashCopy backup in a repository in acomputer system. As illustrated, by way of example only, there are 4space efficient FlashCopy target volumes T0, T1, T2, and T3 (the targetvolumes are illustrated as T0, depicted as 1404D, T1, depicted as 1404C,T2, depicted as 1404B, and T3, depicted as 1404A). In a partition phase,a determination is made as to whether a production volume P 1402 exists.Flashcopy backups of the production volume P are illustrated, forexample, by the notation P→T0. Also, there are FlashCopy backups betweennext T3→T2, T2→T1, and T1→T0. In a prepare phase, one of the spaceefficient FlashCopy target volumes T0, T1, T2, and T3 (1404D-A) areretrieved along with a consistency group from the global shared resourcepool 1450. If there are no space efficient FlashCopy target volumes or aconsistency group, these may be created. A FlashCopy map is created. Aconsistency group is also prepared. In a flash phase, the consistencygroup is started. In a verify phase, the usability state are updated.FIG. 14 illustrates keeping and/or maintaining a global pool ofFlashCopy target volumes 1404 and consistency groups that are used fornew FlashCopy backup tasks upon encountering a collision while ingestingan existing FlashCopy Backup, into a repository. In FIG. 14, T0 1404A isingested into the repository 1406. In one embodiment, a repository 1406is a logical entity within the SVC that ingests the content residing onthe flashcopy target volumes 1404. It does so by ingesting stableflashcopy maps and the associated changed grains as a background task.There is a resource conflict between the next FlashCopy (FC) backup(e.g., T3 1404A) and the repository 1406 because T0 is needed to bereused for the next FlashCopy (FC) backup T3 1404A but T0 1404D is beingingested by the repository 1406.

FIG. 15A-B is a flowchart illustrating an additional exemplary method1500 for efficient FlashCopy backup target volume allocation from ashared resource pool while ingesting a FlashCopy backup in a repository.The method 1500 begins (start 1502) by verifying a state of productiontarget volumes in a partition phase (step 1504). The method 1500determines if the verification process was a success (step 1506). If no,the method 1500 raises an error condition (step 1542) and then themethod 1500 ends (step 1544). If the state of production target volumesis verified, the method 1500 gets or retrieves resources from the globalpool of FlashCopy backup target (step 1508). The method 1500 determinesif the resources from the global pool of FlashCopy backup target weresuccessfully retrieved (step 1510). If no, than in a prepare phase, themethod 1500 dynamically allocates a new space efficient flashcopy targetvolume(s) (step 1512). In the prepare phase following step 1512, themethod 1500 determines if the new space efficient flashcopy targetvolume was successfully allocated (step 1514). If no, the method 1500dynamically cleans up any dynamically allocated resources (step 1532),raises an error (step 1542) and ends (step 1544). If yes (from step 1514and also from step 1510), the method 1500 modifies a consistency group(step 1516).

The method 1500 determines if the consistency group was successfullymodified (step 1516). If no, the method 1500 dynamically cleans up anydynamically allocated resources (step 1532), raises an error condition(step 1542) and ends (step 1544). If yes (from step 1518), the method1500 creates FlashCopy backup mappings (step 1520). The method 1500determines if the FlashCopy backup mappings were created (step 1522). Ifno, the method 1500 dynamically cleans up any dynamically allocatedresources (step 1532), raises an error condition (step 1542) and ends(step 1544). If yes (from step 1522), the method 1500 initializes aconsistency group (e.g., a pre-start) (step 1524). The method 1500determines if the consistency group was successfully initialized (step1526). If no, the method 1500 dynamically cleans up any dynamicallyallocated resources (step 1532), raises an error condition (step 1542)and ends (step 1544). If yes (from step 1526), the method 1500 starts aFlashCopy backup (in a Flash phase) (step 1528). The method 1500determines if the FlashCopy backup was successfully started (step 1530).If no, the method 1500 dynamically cleans up any dynamically allocatedresources (step 1532). From step 1532, method 1500 raises an errorcondition (step 1544) and then the method 1500 ends (step 1546).

If yes (from step 1530), the method 1500, in the flash phase, notifies acopy data services (CDS) of the new space efficient flashcopy backup(step 1534). The method 1500 determines if the CDS was successfullynotified of the new space efficient flashcopy backup (step 1536). If no,the method 1500 raises an error condition (step 1542) and then themethod 1500 ends (step 1543). If yes (from step 1536), the method 1500,in a verify/verification phase, updates the usability of states of thespace efficient flashcopy backups and/or enables monitoring of thestates and/or existing space efficient flashcopy backup target volumes(step 1538). The method 1500 determines if the usability of states ofthe existing space efficient flashcopy backups was successfully updatedand/or the monitoring of the states and/or existing space efficientflashcopy backup target volumes was successfully enabled (step 1540). Ifno, the method 1500 raises an error condition (step 1542). The method1500 ends (step 1544). In addition, after a backup residing on a PIT isingested into the repository, the vdisks and consistency groups, onwhich the original backup resided, may be returned to the shared poolfor future use.

In one embodiment, the present invention provides a solution fordynamically allocating a new FlashCopy target volumes for new FlashCopybackup tasks to avoid the collision that can occur when reusing existingFlashCopy target volumes as described above. This enables significantusability enhancements allowing the computing system to continue toingest existing FlashCopy backups residing on target volumes unimpeded.It also allows the customer to meet their backups window/RPO.

During Flashcopy/snapshot backup, new volumes and flashcopy maps arealways allocated, thus avoiding collision reusing the same target vdiskthat is also being ingested into the repository as described herein.

FIG. 16A-B is a flowchart illustrating an additional exemplary method1600 for efficient FlashCopy backup target volume allocation. Also, themethod 1600 illustrates efficient FlashCopy backup target volumeallocation while ingesting a FlashCopy backup in a repository. Themethod 1600 begins (start 1602) by verifying a state of productiontarget volumes in a partition phase (step 1604). The method 1600determines if the verification process was a success (step 1606). If no,the method 1600 raises an error condition (step 1638) and ends (step(1640). If yes, than in a prepare phase, the method 1600 dynamicallyallocates a new space efficient flashcopy target volume(s) (step 1608).In the prepare phase following step 1608, the method 1600 determines ifthe new space efficient flashcopy target volume was successfullyallocated (step 1610). If no, the method 1600 dynamically cleans up anydynamically allocated resources (step 1628). From step 1628, method 1600raises an error condition (step 1638) and then the method 1600 ends(step 1640).

If yes (from step 1610), the method 1600 creates a consistency group(step 1612). The method 1600 determines if the consistency group wassuccessfully created (step 1614). If no, the method 1600 dynamicallycleans up any dynamically allocated resources (step 1628), raises anerror (step 1638) and ends (step 1640). If yes (from step 1614), themethod 1600 creates FlashCopy backup mappings (step 1616). The method1600 determines if the FlashCopy backup mappings were successfullycreated (step 1618). If no, the method 1600 dynamically cleans up anydynamically allocated resources (step 1628), raises an error (step 1638)and ends (step 1640). If yes (from step 1618), the method 1600initializes a consistency group (e.g., a pre-start) (step 1620). Themethod 1600 determines if the consistency group was successfullyinitialized (step 1622). If no, the method 1600 dynamically cleans upany dynamically allocated resources (step 1628), raises an error (step1638) and ends (step 1640).

If yes (from step 1622), the method 1600 starts a FlashCopy backup (in aFlash phase) (step 1624). The method 1600 determines if the FlashCopybackup was successfully started (step 1626). If no, the method 1600dynamically cleans up any dynamically allocated resources (step 1628),raises an error (step 1638) and ends (step 1640).

If yes (from step 1626), the method 1600, in the flash phase, notifies acopy data services (CDS) of the new space efficient flashcopy backup(step 1630). The method 1600 determines if the CDS was successfullynotified of the new space efficient flashcopy backup (step 1632). If no,the method 1600 raises an error condition (step 1638) and then themethod 1600 ends (step 1640).

If yes (from step 1632), the method 1600, in a verify/verificationphase, updates the usability of states of the space efficient flashcopybackups and/or enables monitoring of the states and/or existing spaceefficient flashcopy backup target volumes (step 1634). The method 1600determines if the usability of states of the existing space efficientflashcopy backups was successfully updated and/or the monitoring of thestates and/or existing space efficient flashcopy backup target volumeswas successfully enabled (step 1636). If no, the method 1600 raises anerror condition (step 1638). From step 1638 and 1636, the method 1600ends (step 1640).

After the Flashcopy backups are ingested into the repository, theFlashCopy mappings, the consistency group, and target volumes (e.g.,target vdisks) where the backup originally resided are deleted by theFlashCopy Manager (FCM). For example, referring to T0 as illustrated inFIG. 10, after the backup residing on T0 is ingested into therepository, the FCM deletes the resources for T0.

FIG. 17 is a flowchart illustrating an exemplary method 1700 forefficient FlashCopy backup target volume allocation while ingesting aFlashCopy backup using a processor device in a computing environment.The method 1700 begins (step 1702) by avoiding collision between a newFlashCopy backup and an existing FlashCopy target volume containing anolder FlashCopy backup being ingested into a repository by dynamicallyallocating a new FlashCopy target volume for the new FlashCopy backup(step 1704). The method 1700 ends (step 1706).

In one embodiment, provided for marking a Flashcopy backup using aprocessor device in a computing environment. In one embodiment, by wayof example only, upon an indication that a Flashcopy backup is not to beingested, ingesting changed grains and a Flashcopy Map (Fcmap) of theFlashcopy backup or alternatively just the Flashcopy Map (Fcmap) of theFlashcopy backup into a repository and dynamically marking the Flashcopybackup for collapse from a first repository into one of a multiplicityof repositories without breaking a flashcopy chain. The collapse may beperformed immediately upon ingest or it may be performed asynchronously.The first repository may entail a pool containing a Flashcopy dependencychain or a Flashcopy cascade.

As mentioned previously, a copy of the production volume at any point intime can be recreated nearly instantly from a first or one of amultiplicity of repositories. Customers may also mount a snapshot backupand use a TSM client to offload the data to TSM server attached storagefor longer-term retention. However, a challenge is presented when a newtarget volume to be mounted to a host gets inserted into the chaindownstream from the point in time that the user requests. The new volumecreates an unstable map downstream which can prevent ingest of backupPITs. Thus, the present invention provides a solution for creating astable Flashcopy Map (fcmaps) for ingest.

FIG. 18 is a flowchart illustrating an exemplary method 1800 forcollision avoidance using dynamic target volume allocation in whichaspects of the present invention may be realized. The method 800 begins(step 1802) by avoiding a collision between a new Flashcopy backup andan existing Flashcopy target volume containing an older Flashcopy backupbeing ingested during one of a mount operation, a restore operation, anda clone operation by dynamically allocating a new Flashcopy targetvolume for the new Flashcopy backup (step 1804). The method 1800 ends(step 1806).

FIG. 19A-B is a block diagram showing an exemplary hardware structure1900 and 1950 for a file level restore operation. As illustrated, aprecondition, by way of example only, has 4 Flashcopy SE target vdiskspredefined as a space efficient Flashcopy target volumes T0, T1, T2, T3,and T4 (the target volumes are illustrated as T0, depicted as 1904A, T1,depicted as 1904B, T2, depicted as 1904C, T3, depicted as 1904D, and T4,depicted as 1904E, The production volume P 1902 schedules Flashcopybackups of the production volume P. For dynamic volume allocation of thetarget volumes, since target vdisk T0 1004A is being ingested into therepository 1906. This is signified by the following notation P→T0. Also,there are Flashcopy backups between next FC backup P→T4→T3→T2→T1→T0. Itdoes so by ingesting stable flashcopy maps and the associated changedgrains as a background task. Since T0 and T1 have been fully ingestedinto the repository 1906.

Since the target volume T2 1904C is being ingested into the repository1906 and also the target volume T2 1904C is being mounted onto a host1908, there is a conflict and a collision occurs. The mount operationcauses write operations to T2, which conflicts with the ingestion oftarget volume T2 1904C into the repository 1906.

Upon the mount operation to the host 1908 there are persistent writes tothe target volume (e.g., target volume T2 1904C) to change the datastorename to “source_backupID” and changes a VMX file (e.g., .VMX file) tosource_backupID. Upon detach these changes are still present on thevolume. Thus, consider the following cases analyses.

Case Analysis 1). A target volume (T2 1904C target volume) content hasalready been ingested into the repository 1906 before the host attachoccurs and before a write. A Flashcopy manager (FCM) may handle arestore operation of a recovery point that has been attached as well asone that has not. However, the FCM tracks which recovery points havebeen attached (and thus modified) so there is a need to ensure that FCMknows if a recovery point in the repository has been modified beforeingest or not. Mounting will block Flashcopy volumes rotating.

Case Analysis 2). The target volume T2 1904C content is in the middle ofbeing ingested into the repository 1906 while an attach is taking placeA mount/attach operation to a host would not be able to proceed untilthe existing ingest completes. Hence, a device agent blocks a mountrequest of an Flashcopy target set if it is in process of beingingested, however this may be less efficient. The Flashcopy manager(FCM) may handle a restore operation of a recovery point that has beenattached as well as one that has not. However, the FCM tracks whichrecovery points have been attached (and thus modified) so there is aneed to ensure that FCM knows if a recovery point in the repository hasbeen modified before ingest or not.

Case Analysis 3). The target volume T2 1904C has not been ingested andan attach is initiated. Again the device agent may make a call toreceive permission to proceed with the attach operation. In this case,there are at least 2 options. Option 1: The computing system would notgrant permission until after the target volume has been ingested. Thismay cause usability problems in the case where ingest was slowed downfor some reason. Option 2: the computing system would not block themount/attachment operation, but target volumes T2 1904C, T3 1904D, andT4 1904E copies are not valid. The Flashcopy manager (FCM) may handle arestore operation of a recovery point that has been attached as well asone that has not. However, the FCM tracks which recovery points havebeen attached (and thus modified) so there is a need to ensure that FCMknows if a recovery point in the repository has been modified beforeingest or not.

Thus, FIG. 19B illustrates collision avoidance using dynamic targetvolume allocation by avoiding a collision between a new Flashcopy backupand an existing Flashcopy target volume containing an older Flashcopybackup being ingested during one of a mount operation, a restoreoperation, and a clone operation by dynamically allocating a newFlashcopy target volume for the new Flashcopy backup. T0 1904A is reusedas a new target volume since the content of T0 1904A already exists inthe repository 1906. At this point, a Flashcopy from T2 1904C to T01904A is established with a copy rate of zero (0). This allows theingestion of T2 1904C, into the repository, to fully complete withoutany impediments. Also, modifications to the T0 1904A, which is the newtarget volume which is located in the repository, to be modified duringthe mount phase of a restore operation without impacting the original T21904C.

As part of the mount operation and/or the restore operation processing,the FCM will not directly mount the managed target volumes or repositoryvolumes containing the original/older Flashcopy backup (e.g., the backupPIT). Instead a copy of the original Flashcopy backup is created bycreating temporary space efficient volumes and establishing FlashCopymappings between the volumes containing the original/older Flashcopybackup and the temporary space efficient volumes. The temporary spaceefficient volumes are mounted on the application host. Reads and writesmay occur on the temporary space efficient volumes such that theoriginal volumes containing the original copy of the original/olderFlashcopy backup remain unchanged.

Upon an un-mount operation or completion of the restore task, FCM willremove the FlashCopy mappings between the volumes containing theFlashcopy backups and the temporary volumes that were exposed to thehost 1908 and will discard the temporary volumes. This avoids theconflict described in FIG. 19A.

FIG. 20 is a block diagram showing an exemplary hardware structure 2000for a high level flow of a file level restore operation. As illustrated,a precondition, by way of example only, has 3 Flashcopy SE target vdiskspredefined as a space efficient Flashcopy target volumes T0, T1, and T2(the target volumes are illustrated as T0, depicted as 2004A, T1,depicted as 2004B, T2, depicted as 2004C). The production volume P 2002schedules Flashcopy backups of the production volume P. For dynamicvolume allocation of the target volumes, since target vdisk T0 2004A isbeing ingested, into the host 2008. Also, there are Flashcopy backupsbetween next FC backup P→T2→T1→T0. It does so by ingesting stableflashcopy maps and the associated changed grains as a background task. Astorage device agent (not shown) is initialized and obtains a validdevice class profile using the command “DEVICE_CLASS profile”. Thestorage device agent is provided the characteristics of the device andall of the parameters (e.g., WRITABLE_NONPERSISTENT_DEDICATED_COPY,target pool for allocation) are validated.

In a mount phase, the original target volume T0 2004A, is used since itis the original Flashcopy backup, thus a new target volume is created.This is shown in FIG. 20 as T1 2004B. The consistency group is stoppedand the fcmap is deleted. At this a new fcmap and a new consistencygroup is created. The consistency group is prepared. The consistencygroup is started and a host mapping is created.

In the file level copy and/or restore operations step, the FCMcore/application code copies the files at the application level to thedestination 2008 (e.g., host) from the target volume (e.g., 2004B) thatis needed to be ingested. During an unmount phase, the host mapping isremoved from the host 2004, the consistency group, the fcmap, and thenew target volume disk which are in the host are each deleted.

FIG. 21 is a flowchart illustrating an exemplary method 2100 forcollision avoidance by dynamically reusing a target volume in whichaspects of the present invention may be realized. The method 2100 begins(step 2102) by dynamically reusing an existing Flashcopy target volumecontaining an older Flashcopy backup and a consistency group for one ofa mount operation, a restore operation, and a clone operation (step2104). The method 2100 ends (step 2106).

FIG. 22 is a flowchart illustrating an exemplary method 2200 collisionavoidance using dynamic target volume allocation from a shared resourcepool in which aspects of the present invention may be realized. Themethod 2200 begins (step 2202) by dynamically reusing from a global poolof allocated resources an existing Flashcopy target volume containing anolder Flashcopy backup and a consistency group for one of a mountoperation, a restore operation, and a clone operation when dynamicallyallocating a new Flashcopy target volume for the new Flashcopy backup(step 2204). The method ends (step 2204).

FIG. 23 is a block diagram showing an exemplary hardware structure for ahigh level flow of a file level restore operation for collisionavoidance using dynamic target volume allocation from a shared resourcepool. As illustrated, a precondition, by way of example only, has 2Flashcopy SE target vdisks predefined as a space efficient Flashcopytarget volumes T1 and T2 (the target volumes are illustrated as T1,depicted as 2304 a, and T2, depicted as 2304B). The production volume P2302 schedules Flashcopy backups of the production volume P. For dynamicvolume allocation of the target volumes, since target vdisk T0 1004A isbeing ingested into the repository 2306. This is signified by thefollowing notation P→T2. Also, there are Flashcopy backups between nextFC backup P→T2→T1. It does so by ingesting stable flashcopy maps and theassociated changed grains as a background task. There is a global poolof shared resources 2325 that is available for collision avoidance usingdynamic target volume allocation from a shared resource pool 2325.

A storage device agent (not shown) is initialized and obtains a validdevice class profile using the command “DEVICE_CLASS profile”. Thestorage device agent is provided the characteristics of the device andall of the parameters (e.g., WRITABLE_NONPERSISTENT_DEDICATED_COPY,target pool for allocation) are validated.

In a mount phase, the original target volume T1 2304A, is reused sinceit is the original Flashcopy backup, thus a new target volume iscreated. This is shown in FIG. 23 T1 2304A. At this point a new fcmapand a new consistency group is created. The consistency group isprepared. The consistency group is started and a host mapping iscreated.

In the file level copy and/or restore operations step, the FCMcore/application code copies the files at the application level to thedestination 2308 (e.g., host) from the target volume (e.g., 2304A).During an unmount phase, the host mapping is removed from the host 2304,the consistency group is stopped, and the fcmap is deleted. The newtarget volume disk 2304A and the consistency group, which are in thehost, are placed in the global pool of shared resources 2325.

In one embodiment, the present invention provides a solution forefficient Flashcopy backup target volume allocation using a processordevice in a computing environment. In one embodiment, by way of exampleonly, a target volume is dynamically allocated for a new Flashcopybackup by reusing an existing Flashcopy target volume containing olderFlashcopy backups that have been previously ingested into a repositoryand are not currently being used as a source for at least one of a mounttask, a clone task, and a restore task.

In one embodiment, provided for marking a Flashcopy backup using aprocessor device in a computing environment. In one embodiment, by wayof example only, upon an indication that a Flashcopy backup is not to beingested, ingesting only a Flashcopy Map (Fcmap) of the Flashcopy backupinto a repository and dynamically marking the Flashcopy backup forcollapse from a first repository into one of a multiplicity ofrepositories without breaking a flashcopy chain. The collapse may beperformed immediately upon ingest or it may be performed asynchronously.The first repository may entail a pool containing a Flashcopy dependencychain or a Flashcopy cascade.

In one embodiment, the present invention determines whether the olderFlashcopy backups are currently being ingested into the repository andare currently being used as the source for at least one of the mounttask, the clone task, and the restore task.

In one embodiment, the present invention dynamically allocates a newtarget volume for the new Flashcopy backup. In one embodiment, thepresent invention dynamically allocates the new target volume for thenew Flashcopy backup if the existing Flashcopy target volume containsthe older Flashcopy backups that are currently being ingested into therepository and are currently being used as the source for at least oneof the mount task, the clone task, and the restore task.

In one embodiment, the present invention performs all or only a selectedfew of the following elements: dynamically creating the new targetvolume for the new Flashcopy backup in a pool of existing Flashcopytarget volumes, dynamically allocating the new target volume for a nextnew Flashcopy backup from the pool of the existing Flashcopy targetvolumes, dynamically allocating the new target volume for the Flashcopybackup from the pool of the existing Flashcopy target volumes whilesimultaneously ingesting into a repository the existing Flashcopy targetvolume containing the older Flashcopy backups.

In one embodiment, the present invention creates or deletes a mapping ofall Flashcopy backups.

In one embodiment, the present invention provides a solution forefficient Flashcopy backup target volume allocation from a sharedresource pool while ingesting a Flashcopy backup in a repository using aprocessor device in a computing environment. In one embodiment, by wayof example only, a global pool of Flashcopy backup target volumes and aconsistency group in the global pool of Flashcopy backup target volumesis maintained for use by a new Flashcopy backup upon encountering acollision while an existing Flashcopy target volume containing olderFlashcopy backups are being ingested into the repository for dynamicallyallocating a target volume for the new Flashcopy backup.

In one embodiment, the present invention creates the consistency groupin the global pool of Flashcopy backup target volumes.

In one embodiment, the present invention retrieves the target volume andthe consistency group from the global pool of Flashcopy backup targetvolumes for dynamically allocating the target volume for the newFlashcopy backup.

In one embodiment, the present invention creates and/or modifies amapping of the Flashcopy backup.

In one embodiment, the present invention notifies a copy data services(CDS) of a new space efficient flashcopy backup.

In one embodiment, the present invention provides a solution forefficient Flashcopy backup target volume allocation while ingesting aFlashcopy backup using a processor device in a computing environment. Inone embodiment, by way of example only, the present invention avoidscollision between a new Flashcopy backup and an existing Flashcopytarget volume containing an older Flashcopy backup being ingested into arepository by dynamically allocating a new Flashcopy target volume forthe new Flashcopy backup.

In one embodiment, the present invention continuously ingests theFlashcopy backup on the an existing Flashcopy target volume into therepository while dynamically allocating the new Flashcopy target volumefor the new Flashcopy backup.

In one embodiment, the present invention dynamically allocates the newFlashcopy target volume and a Flashcopy map.

In one embodiment, the present invention creates a consistency group andthe Flashcopy map, and/or deletes the consistency group, the Flashcopymap, and/or the existing Flashcopy target volume containing the olderFlashcopy backup after the older Flashcopy backups are ingested into therepository.

In one embodiment, the present invention provides a solution creating astable Flashcopy Map (fcmaps) for ingest by dynamically allocating a newtarget volume and a Flashcopy map (fcmap) for ingest upon one of a mountoperation, instant restore operation, file level restore operation,and/or a clone operation breaking a FlashCopy chain.

In one embodiment, the present invention performs at least one ofdynamically inserting the new target volume for the mount operation intothe Flashcopy chain, and/or synchronously ingesting the fcmap prior todynamically inserting the new target volume for the mount, clone,instant restore, and/or file level restore operation into the Flashcopychain.

In one embodiment, the present invention provides multiple independentread and write copies of point-in-time (PIT) backups from a pool ofstorage volume controllers (SVC) for the mount operation.

In one embodiment, the present invention performs at least one ofrequesting permission for the mount, clone, instant restore, or filelevel restore operation, and/or synchronously ingesting the fcmap priorto dynamically allocating the mount, clone, instant restore, or filelevel restore operation upon receiving a request for the new targetvolume for the mount operation if the new Flashcopy backup beingingested is behind in time from a PIT backup, wherein the fcmap isstable and not changing.

In one embodiment, the present invention dynamically allocates a newtarget volume and a Flashcopy map (fcmap) for ingest upon one of a mountoperation and a clone operation breaking a FlashCopy chain. The presentinvention dynamically creates the new target volume for the newFlashcopy backup using a pool of existing Flashcopy target volumes.

In one embodiment, the present invention performs at least one ofcreating an fcmap for the mount operation, preparing and starting aconsistency group for the mount operation, and/or creating a hostmapping for the mount operation.

In one embodiment, the present invention prohibits the new target volumefrom being removed from the Flashcopy chain until the PIT backup, whichis ahead in time from the new target volume, is fully ingested into therepository.

In one embodiment, the present invention provides a solution forefficient repository ingest of a target volume without breaking aFlashcopy chain using a processor device in a computing environment. Inone embodiment, by way of example only, a cloned target volume iscreated by cloning a production volume without breaking a Flashcopychain for continuing an ingestion of a Flashcopy backup target volume.

In one embodiment, the present invention synchronously ingests the fcmapof the production volume and/or dynamically inserts the cloned targetvolume into the Flashcopy chain between the production volume and a nexttarget volume.

In one embodiment, the present invention cloning the cloned targetvolume, wherein a new Flashcopy backup target volume exists and the newFlashcopy backup target volume is empty.

In one embodiment, the present invention performs at least one ofingesting the cloned target volume into the repository for preventing abreaking of the Flashcopy chain, and/or ingesting the new Flashcopybackup target into the repository.

In one embodiment, the present invention marks the cloned target volumefor collapse. In one embodiment, the present invention creates an fcmapof the production volume during the clone operation.

In one embodiment, the present invention provides a solution forefficient repository ingest of a target volume without breaking aFlashcopy chain using a processor device in a computing environment. Inone embodiment, by way of example only, the method dynamically creates acloned target volume by cloning a production volume without breaking aFlashcopy chain for continuing an ingestion of a Flashcopy backup targetvolume.

In one embodiment, the present invention synchronously ingests the fcmapof the production volume.

In one embodiment, the present invention dynamically inserts the clonedtarget volume into the Flashcopy chain between the production volume anda next target volume, and/or clones the cloned target volume, wherein anew Flashcopy backup target volume exists and the new Flashcopy backuptarget volume is empty.

In one embodiment, the present invention performs at least one of:ingesting the cloned target volume into the repository for preventing abreaking of the Flashcopy chain, and/or ingesting the new Flashcopybackup target into the repository.

In one embodiment, the present invention marks the cloned target volumefor collapse. In one embodiment, the present invention creates aFlashcopy map (fcmap) of the production volume during the cloneoperation.

In one embodiment, the present invention provides a solution for markinga Flashcopy backup using a processor device in a computing environment.In one embodiment, by way of example only, upon an indication that aFlashcopy backup is not to be ingested, ingesting changed grains and aFlashcopy Map (Fcmap) of the Flashcopy backup into a repository anddynamically marking the Flashcopy backup for collapse from a firstrepository into a second repository without breaking a flashcopy chain.

In one embodiment, the present invention ingests the fcmap prior todynamically inserting a next target volume into the repository and/orprevents the collapse of the Flashcopy backup into the secondaryrepository until the next target volume is ingested into the repository.

In one embodiment, the present invention passes at least one parameterfrom a Flashcopy manager for a notification as to whether to ingest ornot ingest the Flashcopy backup. In one embodiment, the presentinvention dynamically marks the changed grains and the Flashcopy Map(Fcmap). In one embodiment, the present invention dynamically schedulesthe Flashcopy backup for the collapse into the secondary repositoryafter the next target volume has been fully ingested into therepository. In one embodiment, the present invention creates a temporarytarget volume and establishing the fcmap between an original targetvolume containing the Flashcopy backup and the temporary target volume.

In one embodiment, the present invention, for efficient Flashcopy backupand a mount, clone, or restore task collision avoidance performs atleast one attempt to reuse an existing FlashCopy target volume that isnot currently being used for at least one of a mount task, a clone task,and a restore task at the same time for a FlashCopy backup. If the atleast one attempt to reuse the existing FlashCopy target volume fails, anew Flashcopy target volume for the Flashcopy backup is dynamicallyallocated.

In one embodiment, the present invention determines whether the existingFlashCopy target volumes are currently being used as a source for atleast one of the mount task, the clone task, and the restore task.

In one embodiment, the present invention dynamically allocates a newtarget volume or reusing the existing FlashCopy target volume whether ornot a repository exists.

In one embodiment, the present invention performs the at least oneattempt to reuse the existing FlashCopy target volume in a Flashcopychain of target volumes after the target volumes in the Flashcopy chainhave been ingested into a repository.

In one embodiment, the present invention provides a solution forefficient Flashcopy backup and a mount, clone, or restore task collisionavoidance using dynamic volume allocation from a shared resource poolusing a processor device in a computing environment. In one embodiment,by way of example only, the present invention dynamically uses aFlashcopy target volume for the Flashcopy backup from a global pool ofFlashcopy backup target volumes shared by a plurality of device classesfor avoiding a collision between the Flashcopy backup and the mount, theclone, or the restore task.

In one embodiment, the present invention provides a solution forefficient Flashcopy backup and a mount, clone, or restore task collisionavoidance using dynamic volume allocation with reuse and from a sharedresource pool using a processor device in a computing environment. Inone embodiment, by way of example only, the method performs at least oneattempt to reuse an existing FlashCopy target volume in a Flashcopychain of target volumes after the target volumes in the Flashcopy chainhave been ingested into a repository that is not currently being usedfor at least one of the mount task, the clone task, and the restore taskat the same time for a FlashCopy backup. If the at least one attempt toreuse the existing FlashCopy target volume fails, dynamically allocate anew Flashcopy target volume for the Flashcopy backup from a global poolof Flashcopy backup target volumes shared by a plurality of deviceclasses.

In one embodiment, the present invention dynamically reuses an existingFlashcopy target volume containing an older Flashcopy backup and aconsistency group for one of a mount operation, a restore operation, anda clone operation. In one embodiment, the present invention dynamicallyreuses a plurality of resources already in existence in a dedicateddevice class for dynamically reusing the existing Flashcopy targetvolume. In one embodiment, the present invention eliminates a trackingof the plurality of resources after dynamically reusing the existingFlashcopy target volume.

In one embodiment, the present invention dynamically reuses from aglobal pool of allocated resources an existing Flashcopy target volumecontaining an older Flashcopy backup and a consistency group for one ofa mount operation, a restore operation, and a clone operation whendynamically allocating a new Flashcopy target volume for the newFlashcopy backup.

In one embodiment, the present invention maintains the global pool ofallocated resources available for reuse, where in the a global pool ofallocated resources include a plurality of target volumes andconsistency groups. In one embodiment, the present invention dynamicallyspreads the global pool of allocated resources amongst a plurality ofdevice classes.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

What is claimed is:
 1. A method for collision avoidance using dynamictarget volume allocation from a shared resource pool by a processordevice in a computing environment, the method comprising: maintaining aglobal pool of allocated resources available for reuse for avoiding acollision between a new Flashcopy backup and an existing Flashcopytarget volume containing an older Flashcopy backup being ingested duringone of a mount operation, a restore operation, and a clone operationwhen dynamically allocating a new Flashcopy target volume for the newFlashcopy backup.
 2. The method of claim 1, further includingdynamically reusing from the global pool of allocated resources anexisting Flashcopy target volume containing an older Flashcopy backupand a consistency group for one of a mount operation, a restoreoperation, and a clone operation.
 3. The method of claim 2, furtherincluding creating a copy of the older Flashcopy backup by creating atemporary target volume and establishing a Flashcopy Map (fcmap) betweenthe existing Flashcopy target volume containing the older Flashcopybackup and the temporary target volume, where in the a global pool ofallocated resources include a plurality of target volumes andconsistency groups.
 4. The method of claim 3, further includingperforming at least one of: mounting the temporary target volume onto ahost, and placing the plurality of target volumes and consistency groupsin the global pool of allocated resources during an unmount operation.5. The method of claim 4, further including removing the fcmap betweenthe existing Flashcopy target volume and the temporary target volumewhen un-mounting the temporary target volume from the host or uponcompletion of the restore operation.
 6. The method of claim 5, furtherincluding managing the FlashCopy backup target volumes by using at leastone of a plurality of high-water marks and a low-water marks.
 7. Themethod of claim 6, further including dynamically spreading the globalpool of allocated resources amongst a plurality of device classes.
 8. Asystem for collision avoidance using dynamic target volume allocationfrom a shared resource pool in a computing environment, the systemcomprising: at least one processor device operable in the computingstorage environment, wherein processor device: maintains a global poolof allocated resources available for reuse for avoiding a collisionbetween a new Flashcopy backup and an existing Flashcopy target volumecontaining an older Flashcopy backup being ingested during one of amount operation, a restore operation, and a clone operation whendynamically allocating a new Flashcopy target volume for the newFlashcopy backup.
 9. The system of claim 8, wherein the at least oneprocessor device dynamically reuses from the global pool of allocatedresources an existing Flashcopy target volume containing an olderFlashcopy backup and a consistency group for one of a mount operation, arestore operation, and a clone operation.
 10. The system of claim 9,wherein the at least one processor device creates a copy of the olderFlashcopy backup by creating a temporary target volume and establishinga Flashcopy Map (fcmap) between the existing Flashcopy target volumecontaining the older Flashcopy backup and the temporary target volume,where in the a global pool of allocated resources include a plurality oftarget volumes and consistency groups.
 11. The system of claim 10,wherein the at least one processor device performs at least one of:mounting the temporary target volume onto a host, and placing theplurality of target volumes and consistency groups in the global pool ofallocated resources during an unmount operation.
 12. The system of claim11, wherein the at least one processor device removes the fcmap betweenthe existing Flashcopy target volume and the temporary target volumewhen un-mounting the temporary target volume from the host or uponcompletion of the restore operation.
 13. The system of claim 12, whereinthe at least one processor device manages the FlashCopy backup targetvolumes by using at least one of a plurality of high-water marks and alow-water marks.
 14. The system of claim 13, wherein the at least oneprocessor device dynamically spreads the global pool of allocatedresources amongst a plurality of device classes.
 15. A computer programproduct for collision avoidance using dynamic target volume allocationfrom a shared resource pool in a computing environment by a processordevice, the computer program product comprising a non-transitorycomputer-readable storage medium having computer-readable program codeportions stored therein, the computer-readable program code portionscomprising: a first executable portion that maintains a global pool ofallocated resources available for reuse for avoiding a collision betweena new Flashcopy backup and an existing Flashcopy target volumecontaining an older Flashcopy backup being ingested during one of amount operation, a restore operation, and a clone operation whendynamically allocating a new Flashcopy target volume for the newFlashcopy backup.
 16. The computer program product of claim 15, furtherincluding a second executable portion that dynamically reuses from theglobal pool of allocated resources an existing Flashcopy target volumecontaining an older Flashcopy backup and a consistency group for one ofa mount operation, a restore operation, and a clone operation.
 17. Thecomputer program product of claim 16, further including a thirdexecutable portion that creates a copy of the older Flashcopy backup bycreating a temporary target volume and establishing a Flashcopy Map(fcmap) between the existing Flashcopy target volume containing theolder Flashcopy backup and the temporary target volume, where in the aglobal pool of allocated resources include a plurality of target volumesand consistency groups.
 18. The computer program product of claim 17,further including a fourth executable portion that performs at least oneof: mounting the temporary target volume onto a host, placing theplurality of target volumes and consistency groups in the global pool ofallocated resources during an unmount operation, and removing the fcmapbetween the existing Flashcopy target volume and the temporary targetvolume when un-mounting the temporary target volume from the host orupon completion of the restore operation.
 19. The computer programproduct of claim 18, further including a fifth executable portion thatmanages the FlashCopy backup target volumes by using at least one of aplurality of high-water marks and a low-water marks.
 20. The computerprogram product of claim 19, further including a sixth executableportion that dynamically spreads the global pool of allocated resourcesamongst a plurality of device classes.